This invention relates to a device for extracting a sugar mass from a vacuum cooker.
Vacuum sugar mass cookers are chiefly used for the production of sugar masses with which boiled sweets, bonbons and sugar drops are manufactured. It is readily apparent that the formulation, or viscosity, of the sugar masses may vary, depending on the different types of sugar-drops and the like that are produced. But whatever the case, the sugar-drops will keep only if the water content present in the end product, i.e. the sugar mass after processing, is extremely low. In order to meet this requirement, the sugar mass is normally vacuum-processed in accordance with a known procedure. Moreover, an effort should be made to prevent crystallization when extracting the sugar mass.
German Pat. No. 820,843 and French Pat. No. 1,366,806 relate to devices specifically designed to treat the sugar masses, said devices comprising a gear pump, whereby in said French patent the gears of the pump are so designed as to run hot during operation. Such devices are unsuitable for extracting vacuum-processed sugar masses, for the mechanical stresses caused by the gears are transmitted to the sugar mass and result in the crystallization thereof. An additional drawback is inherent in those devices which feature heatable gears, as the sugar mass is likely to stick to the gears themselves, especially where considerably high temperature values are attained.
Also the conventional manual extracting method, whereby the crystalline mass is removed in batches by means of trays, presents several shortcomings, including the high number of labourers required, the need to perform the operation at a given work pace, having to introduce the batches into the sweet-manufacturing machine, etc.
Extraction devices featuring conveyor scrolls are also known, for example by German utility model Pat. No. 1,946,227 and by German laid open patent application DE-AS No. 2,121,378, in both of which a conveyor scroll or screw feeder is provided in order to convey the sugar mass from the vacuum cooker to the inlet of the manufacturing machine downstream thereof. In the aforementioned German utility model No. 1,946,227, both the scroll and its housing are cone-shaped along their entire length, while in said German application DE-AS No. 2,121,378, only the outlet section of the scroll, and of the relevant housing, is cone-shaped. This entails a relatively long conveyance path, which in turn implies considerable costs as suitable devices are needed in order to maintain the desired temperature level across the entire path, an additional drawback being that particular procedures must be worked out for sugar masses having different viscosity degrees. Moreover, the considerable friction caused by mechanical displacement, e.g. thrusting, along a relatively long path increases the likelihood of crystallization in the mass which is undergoing treatment.
In addition to the above, German Pat. No. 1,270,939 discloses a sugar mass-extracting device comprising either a couple of extractor rollers or a single such roller, said roller/s co-operating with some special scrapers and thus extracting the sugar mass through its adhesion to said roller/s, conveyance being effected by rotation and delivery through the aforementioned scrapers or through the interaction of the two extractor rollers. An adjustable opening produced in the bottom of the device is designed to let the sugar mass initially fall by gravity onto an underlying conveyor belt. The design features hollow roller shafts for conduction of a heating liquid. The principle underlying these devices is no doubt interesting; all of said devices, however, require the adoption of conveyor belts for the transfer of the extracted mass, for extraction occurs, essentially, by gravity, hence the devices are unable to apply suitable pressure to the sugar mass so as to convey it along an internal path leading to the sweet-processing machine.
A further shortcoming of these devices lies in the difficulty to heat the sugar mass conveyance path so as to maintain the desired temperature. Yet another drawback inherent in this kind of device is that it requires an independent sugar conveyance path, namely one which cannot be designed as an integral part of a self-contained unit.
The effectiveness of this kind of device is further impaired by wear, as resulting from functional contact between the operating members, i.e. between one roller and the other and between said rollers and the scrapers, the abrasive action of the processed sugar mass being utlimately responsible for such wear. Worn functional members may result in heavy losses, as their replacement may imply a considerable amount of idle time for the entire production plant--in some instances, several days running. This may lead to rather serious consequences, as the average output of each such plant is e.g. 1,000 kgs/hour.